1st things first. Bareshafting, and paper tuning will not tell you centershot.
Proof: Centershot your bow using either of these methods. Then change yourpoint weight.Your centershot will change. Why would point weight affect centeshot?

Anyway, The step back method is the only way I have found to find centershot. Using one pin, start shooting at 5 yards, stepping back 5 yards at a time. So you should shoot 5, 10, 15...35. If you arrows make a diagonal down the target your spine is off on your bow. If you make a C shape, you arrow rest is out too far. (They will make a gentle C shape). If you make a backwards C then you rest is too far in. Its that simple.